• Imaging Science in Dentistry
• /
• v.48 no.3
• /
• pp.177-184
• /
• 2018

Purpose: This study was performed to evaluate the influence of voxel size and the accuracy of 2 cone-beam computed tomography (CBCT) systems in the detection of vertical root fracture (VRF) in the presence of intracanal metallic posts. Materials and Methods: Thirty uniradicular extracted human teeth were selected and randomly divided into 2 groups(VRF group, n=15; and control group, n=15). The VRFs were induced by an Instron machine, and metallic posts were placed in both groups. The scans were acquired by CBCT with 4 different voxel sizes: 0.1 mm and 0.16 mm (for the Eagle 3D V-Beam system) and 0.125 mm and 0.2 mm (for the i-CAT system) (protocols 1, 2, 3, and 4, respectively). Interobserver and intraobserver agreement was assessed using the Cohen kappa test. Sensitivity and specificity were evaluated and receiver operating characteristic analysis was performed. Results: The intraobserver coefficients indicated good (0.71) to very good (0.83) agreement, and the interobserver coefficients indicated moderate (0.57) to very good (0.80) agreement. In respect to the relationship between sensitivity and specificity, a statistically significant difference was found between protocols 1 (positive predictive value: 0.710, negative predictive value: 0.724) and 3 (positive predictive value: 0.727, negative predictive value: 0.632) (P<.05). The least interference due to artifact formation was observed using protocol 2. Conclusion: Protocols with a smaller voxel size and field of view seemed to favor the detection of VRF in teeth with intracanal metallic posts.

• Korean Journal of Radiology
• /
• v.22 no.12
• /
• pp.2026-2033
• /
• 2021

Objective: The aim of this study was to compare the diagnostic performances of digital tomosynthesis (DTS) and conventional radiography in detecting osteonecrosis of the femoral head (ONFH) using computed tomography (CT), as the reference standard and evaluate the diagnostic reproducibility of DTS. Materials and Methods: Forty-five patients (24 male and 21 female; age range, 25-77 years) with clinically suspected ONFH underwent anteroposterior radiography, DTS, and CT. Two musculoskeletal radiologists independently evaluated the presence and type of ONFH. The diagnostic performance of radiography and DTS in detecting the presence of ONFH and determining the types of ONFH were evaluated. The interobserver and intraobserver reliabilities of each imaging modality were analyzed using Cohen's kappa. Results: DTS had higher sensitivity (89.4%-100% vs. 74.5%-76.6%) and specificity (97.3%-100% vs. 78.4%-83.8%) for ONFH detection than radiography. DTS showed higher performance than radiography in identifying the subtypes of ONFH with statistical significance in one reader (type 1, 100% vs. 30.8%, p = 0.004; type II, 97.1% vs. 73.5%, p = 0.008). The interobserver agreement was excellent for DTS and moderate for radiography (kappa of 0.86 vs. 0.57, respectively). The intraobserver agreement for DTS was higher than that of radiography (kappa of 0.96 vs. 0.69, respectively). Conclusion: DTS showed higher diagnostic performance and reproducibility than radiography in detecting ONFH. DTS may be used as a first-line diagnostic modality instead of radiography for patients suspected of having ONFH.

• Investigative Magnetic Resonance Imaging
• /
• v.25 no.4
• /
• pp.313-322
• /
• 2021

Purpose: To find diagnostic image features, to compare diagnostic performance of multiphase CT versus gadoxetic acid disodium-enhanced MRI (GAD-MRI), and to evaluate the impact of analyzing Liver Imaging Reporting and Data System (LI-RADS) imaging features, for distinguishing combined hepatocellular-cholangiocarcinoma (CHC) from hepatocellular carcinoma (HCC). Materials and Methods: Ninety-six patients with pathologically proven CHC (n = 48) or HCC (n = 48), diagnosed June 2008 to May 2018 were retrospectively analyzed in random order by three radiologists with different experience levels. In the first analysis, the readers independently determined the probability of CHC based on their own knowledge and experiences. In the second analysis, they evaluated imaging features defined in LI-RADS 2018. Area under the curve (AUC) values for CHC diagnosis were compared between CT and MRI, and between the first and second analyses. Interobserver agreement was assessed using Cohen's weighted κ values. Results: Targetoid LR-M image features showed better specificities and positive predictive values (PPV) than the others. Among them, rim arterial phase hyperenhancement had the highest specificity and PPV. Average sensitivity, specificity, and AUC values were higher for MRI than for CT in both the first (P = 0.008, 0.005, 0.002, respectively) and second (P = 0.017, 0.026, 0.036) analyses. Interobserver agreements were higher for MRI in both analyses (κ = 0.307 for CT, κ = 0.332 for MRI in the first analysis; κ = 0.467 for CT, κ = 0.531 for MRI in the second analysis), with greater agreement in the second analysis for both CT (P = 0.001) and MRI (P < 0.001). Conclusion: Rim arterial phase hyperenhancement on GAD-MRI can be a good indicator suggesting CHC more than HCC. GAD-MRI may provide greater accuracy than CT for distinguishing CHC from HCC. Interobserver agreement can be improved for both CT and MRI by analyzing LI-RADS imaging features.

• Journal of Korean Foot and Ankle Society
• /
• v.20 no.4
• /
• pp.145-151
• /
• 2016

Purpose: To evaluate the reliability of preoperative and postoperative distal metatarsal articular angle (DMAA) measurements and to determine whether such reliability is different in accordance with the foot and ankle fellowship and the number of years in practice. Materials and Methods: Between July 2012 and June 2014, a total of 20 patients (24 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic hallux valgus deformity. DMAA were measured twice with an interval of two weeks between the preoperative and postoperative dorsoplantar radiographs by four observers; two of whom were foot and ankle surgeons (A and B), one knee surgeon, and one senior resident. The intraobserver reproducibility and interobserver reliability were assessed by intraclass correlation coefficients. Moreover, the limit of agreement between the preoperative and postoperative DMAA measurements were assessed using a Bland-Altman plot. Results: The intraobserver reproducibility of the foot and ankle surgeon A, knee surgeon, and senior resident improved from 0.796, 0.575, and 0.586 preoperatively to 0.968, 0.864, and 0.864 postoperatively, respectively. The interobserver reliability of foot and ankle surgeon A-B, foot and ankle surgeon A-knee surgeon, and foot and ankle surgeon A-senior resident improved from 0.874, 0.688, and 0.677 preoperatively to 0.971, 0.917, and 0.838 postoperatively, respectively. Conclusion: The intra- and interobserver reliabilities for DMAA measurement improved after proximal chevron osteotomy. Therefore, the necessity of additional procedures to correct the increased DMAA should be reevaluated after proximal chevron osteotomy in the hallux valgus with an increased DMAA.

• Korean Journal of Radiology
• /
• v.24 no.4
• /
• pp.284-293
• /
• 2023

Objective: To validate a simplified ordinal scoring method, referred to as modified length-based grading, for assessing coronary artery calcium (CAC) severity on non-electrocardiogram (ECG)-gated chest computed tomography (CT). Materials and Methods: This retrospective study enrolled 120 patients (mean age ± standard deviation [SD], 63.1 ± 14.5 years; male, 64) who underwent both non-ECG-gated chest CT and ECG-gated cardiac CT between January 2011 and December 2021. Six radiologists independently assessed CAC severity on chest CT using two scoring methods (visual assessment and modified length-based grading) and categorized the results as none, mild, moderate, or severe. The CAC category on cardiac CT assessed using the Agatston score was used as the reference standard. Agreement among the six observers for CAC category classification was assessed using Fleiss kappa statistics. Agreement between CAC categories on chest CT obtained using either method and the Agatston score categories on cardiac CT was assessed using Cohen's kappa. The time taken to evaluate CAC grading was compared between the observers and two grading methods. Results: For differentiation of the four CAC categories, interobserver agreement was moderate for visual assessment (Fleiss kappa, 0.553 [95% confidence interval {CI}: 0.496-0.610]) and good for modified length-based grading (Fleiss kappa, 0.695 [95% CI: 0.636-0.754]). The modified length-based grading demonstrated better agreement with the reference standard categorization with cardiac CT than visual assessment (Cohen's kappa, 0.565 [95% CI: 0.511-0.619 for visual assessment vs. 0.695 [95% CI: 0.638-0.752] for modified length-based grading). The overall time for evaluating CAC grading was slightly shorter in visual assessment (mean ± SD, 41.8 ± 38.9 s) than in modified length-based grading (43.5 ± 33.2 s) (P < 0.001). Conclusion: The modified length-based grading worked well for evaluating CAC on non-ECG-gated chest CT with better interobserver agreement and agreement with cardiac CT than visual assessment.

• Journal of Veterinary Clinics
• /
• v.35 no.5
• /
• pp.206-210
• /
• 2018

The purpose of this study was to evaluate the reliability and validity of the Force-Sensing Resistor (FSR) for measurement of static hindlimb weight distribution in beagle dogs and to compare these results to a Digital Weighing Scale (DWS). Nine healthy beagle dogs were recruited for this study. Static weight distribution was evaluated four times at intervals of 5 days with each device and two observers to calculate the intra- and interobserver reliability. The intraclass correlation coefficient (ICC) values of the FSR for intraobserver reliability were moderate to good (0.74). The results for the DWS showed poor to moderate (0.56) ICC values for intraobserver reliability. The ICC values for interobserver reliability were 0.53 and 0.61 for FSR and DWS, respectively, indicating poor to moderate agreement. Our findings suggest that the Force-Sensing Resistor can be used to measure static weight distribution in veterinary medicine. However, caution should be taken when comparing measured values of static weight distribution obtained utilizing both the FSR and DWS due to their low positive correlation (R = 0.41, p < 0.01).

• Archives of Craniofacial Surgery
• /
• v.19 no.1
• /
• pp.3-12
• /
• 2018

Background: Millard's rotation-advancement repair, which is used by many surgeons, can make a natural philtral column, but most surgeons use a modification of the rotation-advancement flap. The purpose of this article is to introduce a modification utilized by the authors and to provide detailed surgical procedure. Methods: We retrospectively reviewed 82 patients' medical records and presented surgical technique and outcomes. The main features of the authors' strategy are emphasizing horizontal length of the lip, orbicularis oris muscle duplication for improving the definition of the philtral column, overcorrection of domal portion than the non-cleft side in order to compensate for the recurrence during growth. Two judges rated two times the appearance of the patients' nose and lip using Asher-McDade aesthetic index. Intra- and interobserver reliabilities were determined using Cohen's kappa statistics. Results: All patients recovered eventually after surgery; however, two patients have a minor complications (wound infection in one patient, wound disruption due to trauma in the other patient). The improvement of the aesthetic results can be achieved with this modified Millard technique. Total mean scores of the Asher-McDade index was 2.08, fair to good appearance. The intraobserver reliabilities were substantial to almost perfect agreement and the interobserver reliabilities were moderate to almost perfect agreement. Conclusion: We modified Millard method for repair of complete unilateral cleft lip. The surgical outcomes were favorable in long-term follow-up. We hope our technique will serve as a guide for those new to the procedure.

• Imaging Science in Dentistry
• /
• v.46 no.2
• /
• pp.87-92
• /
• 2016

Purpose: The aim of this study was to assess and compare the diagnostic performance of panoramic and occlusal radiographs in detecting submandibular sialoliths. Materials and Methods: A total of 40 patients (20 cases and 20 controls) were included in this retrospective study. Cases were defined as subjects with a submandibular sialolith confirmed by computed tomography (CT), whereas controls did not have any submandibular calcifications. Three observers with different expertise levels assessed panoramic and occlusal radiographs of all subjects for the presence of sialoliths. Intraobserver and interobserver agreement were assessed using the kappa test. Sensitivity, specificity, accuracy, positive and negative predictive values, and the diagnostic odds ratio of panoramic and occlusal radiographs in screening for submandibular sialoliths were calculated for each observer. Results: The sensitivity and specificity values for occlusal and panoramic radiographs all ranged from 80% to 100%. The lowest values of sensitivity and specificity observed among the observers were 82.6% and 80%, respectively (P=0.001). Intraobserver and interobserver agreement were higher for occlusal radiographs than for panoramic radiographs, although panoramic radiographs demonstrated a higher overall accuracy. Conclusion: Both panoramic and occlusal radiographic techniques displayed satisfactory diagnostic performance and should be considered before using a CT scan to detect submandibular sialoliths.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.5
• /
• pp.726-731
• /
• 2021

Objective : Distinguishing between an infundibulum and a true aneurysm is clinically important. This study aimed to evaluate whether using source image based new three-dimensional rotational angiography (S-n3DRA) can increase the rate of aneurysm detection and improve distinction between a true aneurysm and an infundibulum. Methods : Twenty-two consecutive patients with 23 lesions, were evaluated by time-of-flight (TOF) magnetic resonance angiography (MRA), S-n3DRA, and digital subtraction angiography (DSA). The data were retrospectively and independently reviewed by two neurointerventionists, and the diagnoses based on TOF MRA, S-n3DRA, and DSA were compared. The diagnostic efficacy (interobserver agreement and diagnostic performance) of S-n3DRA was compared with that of TOF MRA. Results : S-n3DRA showed higher interobserver agreement (κ=0.923) than TOF MRA (κ=0.465) and significantly higher accuracy than MRA in distinguishing an aneurysm from an infundibulum (p=0.0039). Conclusion : Compared to MRA, S-n3DRA could provide better screening accuracy and information for distinguishing an aneurysm from an infundibulum. Therefore, S-n3DRA has the potential to reduce the need for DSA.

• Korean Journal of Radiology
• /
• v.25 no.6
• /
• pp.540-549
• /
• 2024

Objective: This study investigated the feasibility and prognostic relevance of threshold-based quantification of myocardial delayed enhancement (MDE) on CT in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods: Forty-three patients with NIDCM (59.3 ± 17.1 years; 21 male) were included in the study and underwent cardiac CT and MRI. MDE was quantified manually and with a threshold-based quantification method using cutoffs of 2, 3, and 4 standard deviations (SDs) on three sets of CT images (100 kVp, 120 kVp, and 70 keV). Interobserver agreement in MDE quantification was assessed using the intraclass correlation coefficient (ICC). Agreement between CT and MRI was evaluated using the Bland-Altman method and the concordance correlation coefficient (CCC). Patients were followed up for the subsequent occurrence of the primary composite outcome, including cardiac death, heart transplantation, heart failure hospitalization, or appropriate use of an implantable cardioverter-defibrillator. The Kaplan-Meier method was used to estimate event-free survival according to MDE levels. Results: Late gadolinium enhancement (LGE) was observed in 29 patients (67%, 29/43), and the mean LGE found with the 5-SD threshold was 4.1% ± 3.6%. The 4-SD threshold on 70-keV CT showed excellent interobserver agreement (ICC = 0.810) and the highest concordance with MRI (CCC = 0.803). This method also yielded the smallest bias with the narrowest range of 95% limits of agreement compared to MRI (bias, -0.119%; 95% limits of agreement, -4.216% to 3.978%). During a median follow-up of 1625 days (interquartile range, 712-1430 days), 10 patients (23%, 10/43) experienced the primary composite outcome. Event-free survival significantly differed between risk subgroups divided by the optimal MDE cutoff of 4.3% (log-rank P = 0.005). Conclusion: The 4-SD threshold on 70-keV monochromatic CT yielded results comparable to those of MRI for quantifying MDE as a marker of myocardial fibrosis, which showed prognostic value in patients with NIDCM.